Safety circuits are used in a variety of applications. A safety circuit typically provides a control over a supply of power to a load, for example. One use of safety circuits is within elevator systems. A daisy chain arrangement of safety switches along a hoistway provides an ability to control whether the elevator machine is powered to cause movement of an elevator car. The switches of the safety circuit along the daisy chain are associated with an elevator door component such as a hoistway door lock. Whenever the door component is not in a properly closed position, the safety switch remains open and interrupts a conductive path along the safety chain. Under these conditions, power is not provided to the elevator machine so that the elevator car cannot move. The safety chain therefore provides an ability to prevent elevator car movement in the event that a hoistway door is not closed or properly locked.
Known safety chains in elevator systems operate based on 110 volt AC power. While such systems have proved reliable and useful over the years, there is a desire to reduce power consumption in elevator systems. One opportunity to reduce power consumption would be to introduce a lower power safety chain circuit. This cannot be done, however, without introducing new design challenges and complexities.